The sediments at Carmel Church include lots of iron, sulfur, and carbonate minerals. When the sediment is exposed to air and water, these materials precipitate out as various minerals that tend to harder the bones, making them much stronger. Unfortunately, the same minerals also form a cement that makes the sediment very difficult to dig through or remove from the bones, and the high acidity damages the surfaces of the bones. We therefore try to remove the bones before they weather, but even if it has already happened we still recover whatever we can. One small advantage is that, with the bones so heavily mineralized, we can sometimes remove them without jacketing.
That’s what we did with one of the dentaries we found yesterday, and rather than having it sit around the quarry all week, we took it to the Caroline County Visitor Center (above). It will be available for viewing during normal business hours through the end of our excavation.
Removing that bone gave us better access to the rest of the pit, and new bones have started showing up. The largest is another possible dentary (our third), laying underneath the one we removed. Here’s an oblique view of the pit, with two dentaries outlined and the location of the one we removed indicated by the dashed line:
Most of the small bones in the back of the pit haven’t been identified yet, but at least one is a small vertebra:
We’ll be at it again tomorrow, but given the dreadful conditions that are forecast I may modify the digging schedule over the next few days.